Answer :
An open class system facilitates vertical (or "upward") mobility. This in theory diminishes the extent to which you have to come from a prominent family to succeed financially in life.
Answer: d. all of the above
Ideally, an open class system is based on social mobility that includes horizontal mobility, intergenerational mobility and vertical mobility. Social mobility is an important factor in countries that want to give their citizens equal chances to succeed in life. Social mobility ensures that people can develop their potential and succeed regardless of their origin, their age, their gender, their social class, or any other factor that is outside their control.